"melodramatic radio serial" (later extended to television), 1939; so-called because sponsors often were soap manufacturers, from earlier horse opera "a Western" (1927). Shortened form soap for this first attested 1943.

soap opera

modifier

: The average man and woman in this country live a soap-opera existence

noun phrase

A radio or television daily dramatic series typically showing the painful, passionate, and riveting amours and disasters of more or less ordinary people: a new soap opera which threatens to out-misery all the others

A life or incidents in life that resemble such shows: You want to hear the latest in my never-ending soap opera?

[1939+; fr the fact that in radio days such shows were typically sponsored by soap manufacturers]

The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D.Copyright (C) 2007 by HarperCollins Publishers.Cite This Source

Idioms and Phrases with soap opera

soap opera

1.

A radio or television serial with stock characters in domestic dramas that are noted for being sentimental and melodramatic. For example, She just watches soap operas all day long. This term originated in the mid-1930s and was so called because the sponsors of the earliest such radio shows were often soap manufacturers.

2.

Real-life situation resembling one that might occur in a soap opera, as in She just goes on and on about her various medical and family problems, one long soap opera.
[ 1940s
]